In the United States, the majority of cataract lenses are removed by a surgical procedure known as phacoemulsification. During this procedure, a cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquefies or emulsifies the lens so that the lens can be aspirated out of the eye. The diseased lens, once removed, is then typically replaced by an artificial lens.
More recently, femtosecond lasers have been proposed for use in cataract surgeries. The femtosecond laser has the capability to assist the fragmentation (laser phacoemulsification or breaking up) of the cataract. Generally stated, the laser applies a number of pulses to the lens in a pre-designed pattern which then allows the surgeon to remove the lens matter. See, e.g., Nagy et al, Initial clinical evaluation of an intraocular femtosecond laser in cataract surgery. J Refract Surg 2009; 25:1053-60.
Prior to inserting the artificial lens, softer or attached cortical material that was not removed during the initial step is aspirated from the eye. Typically, this is done using a tip that is similar to the ultrasound phacoemulsification tip, but with a smaller opening at the distal end and without the ultrasonic vibration. The aspiration tip can also be used to polish the posterior capsule to remove residual cortical fibers or epithelium cells to reduce the risk of posterior capsule opacification or other undesired events. Conventional aspiration tips have been made from titanium or stainless steel with highly polished surfaces to reduce burrs or sharp edges. Other aspiration tips use silicone rubber tip caps that reside over the metal tips. See, U.S. Pat. No. 5,718,677. More recently, dual function aspiration tips such as the MicroSmooth® sleeve from Alcon, Inc., that can both irrigate and aspirate have been used. See also, U.S. Pat. No. 7,967,775. The contents of these patent documents are hereby incorporated by reference as if recited in full herein.
Despite the above tips, often a J-shaped cannula or other tool must be inserted into the capsule bag during capsule polishing to help detach cortical material that is resistant to aspiration using just the aspiration and irrigation tip. Thus, there remains a need for tips that can facilitate cortical clean-up and/or polishing of the capsule bag to prevent posterior capsular opacification.